Sgt. Ron Helus, the sheriff’s sergeant who died saving people during the Thousand Oaks bar shooting last month, was killed by friendly fire, according to officials.

Authorities determined that the suspect, Ian David Long, allegedly shot Helus five times. But investigators say Helus might have survived those wounds had he not been hit a sixth time by a California Highway Patrol officer’s bullet, which was the fatal shot.

Helus was a 29-year veteran of the Ventura County Sheriff’s Office and was scheduled to retire next year. He was killed along with 11 others at the Borderline Bar.

Officials say Helus and the CHP officer went into the bar at the same time. At some point, Helus wound up between the gunman and the officer.

Both the Ventura County Sheriff's Office and CHP stressed that the gunman was solely responsible for the events that unfolded that night.